Pavement or roadway and method of making the same.



PATENTED MAY 26, l1908.

W'. s. HOUEETON. PAVEMENT 0E EOAEWAY'ANDMEEEOD 0E MAKING SAME.

APPLICATION ILIED SEPT 1907 i %\NMN\ mm; W

H18.. .17 H A @E V bak/1M www? y\\`lLL1AM S. HUlhllTON, Ol" BOSTON,MASSMllUSE'lTS.

PAVEMENT OR ROADWAY ANB METHOD 0F MAKNG Stl.

No., asses?.

Specification o1 Letters Patent.

Patented May 26, IQS.

Application led September 23, 1907. Seriai No. 3941.093.

To all whom iz may concern.

Bo it known `that l, WILLIAM S. iionon- TON, a citizen of the UnitedStates, residing at Boston, in the county of Sufiolk and-Stateo'lliassacluisctts have invented a cerl Y tain new and usefulImprovement in Pave ments or Roadways and Methods of Making' Same, ofwhich the following is a full, clear, and exact s iecification,reference being had therein to t e accompanying drawings.

My invention relates to concrete pave ments. Heretofore, pavements ofthis general type have Abeen constructed in courses, comprising afoundation course of concrete or broken stone, a binder and a Wearinvsurface; the )urpose of the binder course heing to form a )ond betweenthe'loundation and the wearing surface. As a rule, the wearing surfacecontains a percentage of bituminous material and to a large extent thisbitumi-V nous material is relied upon to,secure a erfeet adhesionbetween the wearing sur ace and the binding course, or, in cases whereno binding course is employed, between the wearing surface and thefoundation. In such iavements, it is absolutely essential that thewearing course should adhere ierfectly to the under course, otherwise,wien the pavement is subjected to trafiic, the wearlng course is veryliable to slide, roll or buckle and finally break up. This tendency isexaggerated by the susce tibility of b1- tuminous material to heat W ichsoftens it and thereby loosens the bond between the wearing surface andthe underneath course. The object of my invention is to provide a)avement so constructed that any sliding, huckling or other disturbanceof the wearing surface will be impossible.

Further objects are to provide a pavement of durable, elicient andeconomical construction.

In the accompanying drawings, which illustrate my invention and in whichsimilar numbers refer to similar `parts throughout the severalviewsz-Figure 1 is a vertical cross-sectional View of a portion of myoundation or substructure, and Fig. 2 'is a vertical cross sectional`view of a portion of a completed, pavement embodying my invention.

In the drawings, 1 designates a curb; 2, 2, broken or crushed stones; 3cement mixture and 4 a Wearing surface.

My pavement is constructed in the following manner. After the ground orearth has been made compact and smoothed 'then spread thereon a layer ofcrushed or breiten' stone, the stony elements preferably ranging indiameter from one to three inches, end

roll the same until it is compact` The depth of this layer oi crushedsto may vary from four to eight inches. if parte ways and simiiarroadways where the is light, a foundation of four inches in depth would'probably suilice, but where the road. is to be subjected to heavyraiiic, the fourniea tion should be from six to eight inches after beingrolled. For reasons hereinafter explained, it is important that thestonyelements which make up this foundation layer should be of suiiicientsize to ieave large voids throughout the foundation after it has beenrolled.

` l next prepare a mixture oi senil or screenings and dry cement(`1oreierably` Fortland cement), in the proportion or one part oi cementto three or four parts of'sand or screenin'fsand spread this mixtureover the surface of the foundation', The cement miratture is thenwashed, by water from a hose or 1other suitable appliance, into vthevoids in vthe foundation, Where the cement sets and ,binds the stonefoundation into a homogeneous mass. It is desirable and necessary inthis connection that the voids should 'be j of a size suiicient' topermit the cement noirey ture topercolate entirely through theroundation and fill completely the voids from the bottom up. Thiswashing process is reeated until the voids in the foundation ave beenfilled upto aline ranging from one-quarter inch to an inch below theuninet' face or surface of the stone foundation, which at this stagepresents a substantially smooth surface of stone broken un byinnumerable voids of varying depth ano forms.

.After the foundation has been thoroughly bound tovether in a monolithicmass by the setting o? the 'cement mixture, it isv then ready to receivethe Wearing surface which may be composed or made up by any' of the Wellknown methods, or of any preferred composition, J l

The wearing surface 'when laid 'upon the foundation, penetrates and'nils up open voids in the u per iortion of the foon# dation and istherey, W en hard, anchored to the foundation. It Wili be noticed thatmany of the voids are larger at their bottom than at their top and insuch cases, those portions of the Wearing suraee which ill all the loulos

those particular Weide not es enel'lore to hold the weering surface inplace. In n pavement so bonstructed, it ie olor/ions shifting orbuckling of the wearing surnce is absolutely impossible and the pavementis to ell intente ein purposes en integral body.

The principal advantages of my pavement constructed es above set forthare its economy ol eonstrnetion and wearing qualities. The foundationlayer of crushed or broken stone is rolled with the ordinary steamroller whiizh enables the loyer to be smoothed off rapid j; and savesthe expense of-pounding or tamping the layer by hand. Furthermore byrolling, e smoother and more even sul" e can be seemed, end to this factis me Were upper snxfnee of the foundation leyer rough end made up ofalternate stimy projections and depressions. the weering surface betweenthe projections would in time weer away and the surface of the per@ mentwould become uneven and thereby tend to breek up.

By having zr comperatwely smooth upper surface on the foundation-layer,the eroslve effect ol traffic on the wearing surface does not result inroughenng the surface of the pavement, and even when the wearing surfacehas been worn away to the mrsnletonlng/er, pevnwnt is still smooth undeven. lo View L; feature, my paver :ent doeii not :fedi re henryweering,y surlarfe and it may loe mede oompa-rzttlmt any sliding,V

due the Wearing qualities of my pavetively thin il desired. This alsocondnees to economy of construction.

Whitt I oieim is?- 1. pavement, consisting of e foundation layer ofCrushed or broken stone, the pieces of which lieI closely Vtogether in ecompnet mess having e smooth upper surface, the voids in the lowerportion of seid layer being occu ied by e cement mixture which binds allo the ieces of the layer into a monolithic -mess, eno e wearing layer'aneliored to the upper ortion of the foundation leyerluy filling t eupper voids thereof and being 1ntegrnl with the body of the wearinglayer.

2. The process Vof making e pavement, consisting 1n laying a. course ofcrushed or broken stone, rolling the same to com act the course and toernoo th the upper sur eee, then filling the lower voids in seid Coursewith ai liquid Cement mixture, 'permitting said mixture to set andapplying e, suiteble wearing surface to seid structure in such e mannerthat the lower ortion of said weeringeurfeoe fills in all me open voidsin the up er Surface of said course.

n Witness whereof, l have hereunto set my hand, in the resence of twosubseribing Witmesses, this t 1e fifth day of September, 1907.

. WILLAM HOUGHTN. Vifitnesses IE. F. UNMC,

Simmons F. RICHARDSON.

